The present invention relates to a method of breaking up a ship hull, particularly a large ship hull.
In ships, there are generally used a large amount of metal materials of high quality, and when a ship becomes a scrapped vessel, this is broken up into small pieces of metal materials (bar materials, plate materials, shape steels) thereby producing articles of commerce or selling them as scrapped materials.
In the prior art working method of breaking up a ship hull, the portion of hull floating above the sea is cut off into large masses (in general, this is referred to as large separation), these masses are hung up by means of a marine crane or a land overhang crane and disposed on the land and then cut into small pieces (in general, this is referred to as small separation). Next, after the end of the breaking-up of the portion existing above the water surface, the submerged portion existing under the water surface is towed onto a shallow, and waiting the ebb-tide, the hull portion appearing above the water surface thereby is then subjected to said large separation and subsequently to the small separation in the same manner as described above.
In the case of said prior art hull breaking-up method, there are required a place where the hull is moored, a shallow, a quay wall where the broken-up objects are landed, a broad place where the broken-up objects are subjected to the small separation and auxiliary facilities, and it is not always possible to perform the breaking-up operation at any place. As another problem, the two steps of the breaking-up operations, namely the large and small separations are parformed at separate places, so that the transportation by crane is required, and the working number required for said transportation amounts to as much as 30% of the whole working number of breaking-up operation, and also there is a further problem that many workmen are required because the breaking-up working locations are distributed at a plurality of points.
Under such circumstances, the prior art working method has a severe limitation to the breaking-up place and requires many workmen, so that it is inevitable for the scraps or metal materials usable immediately to become high in value.